Ornithine carbamoyl transferase activity. Use of a bovine liver extract in quality control.

To obtain a pure ornithine carbamoyltransferase for quality control in clinical chemistry, the authors compared human plasma and bovine liver ornithine carbamoyltransferase. The data show that the KM of both enzymes are similar (respectively 1.03 and 1.33 mmol when ornithine is used as substrate; 1.02 and 1.06 mmol with carbamyl phosphate). The following properties are shown to be equivalent: linearity of the enzymatic reaction, inhibition by higher substrate concentrations, and temperature denaturation. The similarities between the two enzymes indicate that bovine liver ornithine carbamoyltransferase can be used in clinical chemistry quality control.